Built in 1993, this house and privy were designed by Mr Lowell with a bridge and moat around them for guests staying in the Red Oak II guest houses who had brought their mother-in-law along. The idea was that the mother-in-law could stay in this tiny house while the drawbridge was raised so others could enjoy a peaceful stay at Red Oak II. The pond north of the Mother-in-Law's House was dug to provide a pond for the south side of Red Oak II. The building is now known as the Otis Cabin after Mr. Lowell renamed it for Otis the bullfrog, who lives with his family in Otis Pond. The drawbridge is now a wooden walkway, and the building and pond are very popular with visitors to Red Oak II.